Solvent controlled sugar-rhodamine fluorescence sensor for Cu2+ detection

A turn-on fluorescence probe for Cu2+ detection has been reported according to a Cu2+ triggered spirolactam ring-opening reaction. The probe is a double-responsive fluorescent and colorimetric Cu2+-specific sensor in aqueous solution containing 20% of acetonitrile with high selectivity and excellent sensitivity (limit of detection is 12 mu g L-1). Furthermore, the significant color changes visible to the naked eye at the concentration of 3 mu M (ca. 0.20 mg L-1) are about ten times lower than the WHO (World Health Organization) recommended level (2.0 mg L-1) for Cu2+ ions in drinking water.